So glad you are posting about this. I felt like I was the only one here. And although I'm sure that's not quite true, it does seem like a secret. A stock class racer first told me about how the car always slower when they took out that heavy secondary spring from the DC distributor. I didn't learn the real reason for most of the delay until much later.

This is the reason for the solid line and the dashed line in the Direct Connection graph in post #11 here:
https://www.forabodiesonly.com/mopar/thr...post-1972040585
In theory the timing could increase (depending on the spring perch setting) but on a slow ECU, its flat, which is still a hell of a lot better than losing timing.

They set up the heavy spring and weights to counteract the delay in electronic switching (sometimes called slew rate). Every electronic operation takes time.

This secondary portion of the advance can't be done with all advance mechanism. That's with the MSD, my suggestion for Dave was to set it up to delay the 'all in' to a higher rpm. That way the slew will have less effect through the top of your power curve.
https://www.tapatalk.com/groups/racingfu...-less-t765.html

More links on slew in Innova 3568 Timing Light, now slew rate